Shoes such as sneakers, bags, or clothes such as sweat suits, hats or the like are generally provided with adjustment strings (hereinafter, referred to as ‘string’) for adjusting the waist size or head size to be fit into users' bodies after the users put them on or if necessary. The string typically has a fixation clip moving along the string at an end of the string so as to keep the length of the string constant.
The clip acts to prevent the string from being moved along the string in close contact with the string when the string passes through the central portion of the clip, and allows the close contact to be released and moved along the string again by means of a press operation of the user, thereby adjusting the length and shape of the clothes or hats to suit user's taste.
However, the clip inconveniently causes the user to individually and separately adjust the string length at the time of adjusting the length.
In addition, an extra string may get in the way or may be entangled while the entire length of the string keeps the same. It is also difficult to separate the string from the clip, so that the clip may hit the inside of the washing machine to cause the washing machine to be damaged or may cause the clothes or the washing machine to be damaged at the time of washing the clothes.
In view of the foregoing, the present inventors have proposed the string length adjustment device that can solve the problems associated with the clip described above and are notified of Korean Patent Registration No. 929587.
Korean Patent Registration No. 929587 relates to the string length adjustment device in which a coupling unit consisting of an elastic spring, a cap and a bolt is fixed to a lower portion of a coupling unit guide shaft (drum rotation axis) of a winding drum, and a rotation housing can be rotated in either forward or reverse direction when the cap is disposed in an upper region of the spring by virtue of the spring operation and can be rotated only in one direction when the cap is disposed in a lower region of the spring.
However, in the case of the string length adjustment device, the coupling unit guide shaft of the winding drum should be typically made of metal in order to ensure the durability of the device, and the manufacturing unit cost of the string length adjustment device may be increased and the string length adjustment device may be failed due to spring deformation or deviation. In addition, since the winding portion around/from which the string is wound/unwound is integrally formed with the rotation housing and operates together all the time, the string may be entangled within the device to cause the device to be out of control or to cause the device itself to be damaged when the user arbitrarily rotates the knob (rotation housing or housing cap) in an excessive or forcible way in the unwinding direction without pulling and loosely untying the string of shoes in the unwinding state.
The present inventors have therefore invented and proposed a novel string length adjustment device by not using components such as metallic coupling unit guide shafts, adjustable curve-type elastic springs, or the like to thereby reduce the product unit cost and improve the assembly and also by improving the structure of the device such that the rotation housing and the winding drum are integrally rotated in one direction in the winding state and only the winding drum is rotated in either forward or reverse direction in the unwinding state to thereby enhance the operational stability and reduce the rate of failure.